Electrical connector contacts



April 25, 1967 M. A. JURIS r-:TAL 3,316,528

ELECTRICAL CONNECTOR CONTACTS Filed July l, 1964 f1 2 uenfars/ [fawJ'ence United Statespatent O V3,316,528 V ELECTRICAL` CONNECTORvCONTACTS Mitchell A. Juris, Chicago.and,.loseph A. Storcel, NorthRiverside, Ill., and Lawrence T. Lhota, Granada Hills,

Calif., assignors to-Amphenol Corporation, a corporation of DelawareFiled July 1, 1964, Ser. No. 379,626 1 Claim. (Cl. 339-259) Thisinvention relates to electrical connectors and more particularly to animproved type of sleeve contact, shown in the present disclosure in aform adapted to utilization in a connector of the hermetically sealedtype.

It is the general aim of the invention to provide a sleeve contactadapted to mate with a conventional cylindrical contact pin wherein thesleeve is of such design and construction -as to be more satisfactoryand more dependable than types heretofore developed. More specifically,it is among the objects of the present invention to provide a sleevecontact having low inherent resistance and relatively highcurrent-carrying capacity, yet, at the same time being of compactmechanical design, completely enclosed, and of electrical and mechanicaldesign capable of long-extended use and well capable of withstandingimproper usage or abuse. In this connection, it may be pointed out thatin certain exacting connector applications, it is essential that themillivolt drop existing across a pair of contacts be as low as possible,yet at the same time, it is equally important that the contact design besuch that the sleeve is not subject to damage by the insertion of anoversize pin or test probe. This is accompli-shed in the presentinvention with an arrangement such that the electrical cur-rent pathextends only through a single piece of metal which need have very littleinherent resilience in itself since the mating contacts are held inresilient engagement, as tightly as desired, by a tempered spring membercapable of withstanding high operating temperatures without damage,compactly arranged, and in an assembly wherein all critical parts of thecontact assembly are completely enclosed.

A present preferred embodiment of the invention is illustrated in thedrawings attached to and forming a part of the present specific-ation,wherein FIGURE 1 is a cross-sectional view of an hermetically sealedelectrical connector having contacts as disclosed herein;

FIGURE 2 is a central sectional view of a socket contact as contemplatedby the present invention;

FIGURE 3 is a side elevational View of a helical coil spring employed inthe contact and FIGURE 4 is a fragmental sectional view similar toFIGURE 2 but showing a mating contact pin within the socket contact.

In the connector shown in FIGURE l, the receptacle shell may beconventional. Such shells are ordinarily of unitary metal construction,generally having a mounting ange 11 and screw threads 12, flattened at13 for mounting in a panel or bulkhead. Ordinarily, one or more bayonetstuds 14 are provided for engagement with a mating plug, and keyways V15may be formed on the interior of the shell in appropriate arrangement totit corresponding keys on the plug. Suitable sealing means, such as theO-ring 16, may be provide-d.

A typical connector will include one or more contact members supportedin a glass or ceramic sealing member 17, hermetically sealed within thereceptacle shell and bonded to the mounting shank portions of theindividual 3,316,528 Patented Apr. 25, 1967 Y contacts 18. The forwardends of the in-dividual contacts extend through an insulating insert 19to a position such that they are accessible from the front face of thereceptacle.

The individual contacts 18 each include a mounting Vshank 20 having aknurled portion 21 thereon with a solder pocket 22 at the rearward endof the contact to receive a flexible conductor and thin Walled splitsleeve pin socket 23 at the forward end of the contact. As shown, thesplit sleeve 23 is divided into .a pair of generaly semi-circular colletjaws by a longitudinal slot 24 andthe outer diameter of the sleeve isturned down between shoulders 25 and 26 to receive a coiled contractionspring 27. The spring 27 (FIGUREl 3) is preferably formed of a narrowstrip or ribbon of thin, flat, heattreated metal such as berylliumcopper, having -a high degree of resiliency and capable of withstandingelevated temperatures without dam-age. The spring 27 and the splitsleeve portion 23 of the contact are enclosed and protected by a tubularhood 28, having a skirt 29 presstted on the knurled portion 21 of thecontact shank 20.

The forward end of the hood has an inwardly directed ilange 30 toprovide a limiting orifice 31 of iixed diameter; large enough to admit aContact pin 32 of proper size, (FIGURE 4) but small enough to exclude anoversize contact pin or test probe. The tubular portion 28 of the hoodis of internal diameter such that, while some expansion and contractionof the split sleeve and spring 27 will occur, (FIGURE 4), the expansionwill be so limited that the elastic limit of the parts cannot beexceeded. It follows that the sleeves are not apt to be damaged bymisalignment of the mating pin contacts, or by use of a test probe.

At the same time, it should be observed that the effect of the coilspring on the thin-walled split sleeve will be to cause the sleeve tosnugly grip the pin along the entire length of their telescopingengagement, insuring the best possible electrical union.

From the foregoing, it will be appa-rent that an electrical contactconstructed in accordance with the present disclosure will not only behighly `resistant to ldamage and abuse, but will also have inherentlyhigh electrical conductivity and low millivolt drop. This isaccomplished by the unique ar-angement of parts whereby the electricalpath extends through only a single piece of metal, which may be of ahigh conductivity metal since this piece in itself need not have anyconsiderable degree of springiness or resilience, yet the resiliencynecessary to adequately grip a mating contact pin is afforded by thecoil spring 27, which ydoes not necessarily conduct any electrical cur-Irent. The arrangement of the contact sleeve is simple, compact, yandwell protected since both the sleeve and the spring are at all timescompletely enclosed by the hood portion, the mouth of which is of theclosed entry type, having an aperture sized to exclude oversize pins orprobes, and to thus minimize any possibility of damage by misuse.

We claim:

In an electrical connector, a contact comprising a relatively lon-gslender body portion consisting of a single integral piece of highconductivity metal having a rearward end including means for -attachinga ilexible conductor thereto and having a forward end including agenerally cylindrical split sleeve comprising a pin socket, said socketbeing split into a plurality of separate individual jaws in opposedrelationship to each other, with said split sleeve having a reducedouter diameter portion extending between a rearwardlyv facing shoulderadjacent the front ofthe `sleeve and forwardly facing -shoulder adjacentthe rearward end of said sleeve; a tubular hood for providing t alimiting orifice of fixed dimension surrounding vand enclosing saidsplit sleeve and closely spa-ced with respect to the outer surfaces ofthe aforesaid jaws, together with a relatively flat, thin radialcompression coil spring of plural helical convolutions encircling andintimately` contacting the aforesaid split sleeve substantially alongthe -ull distance between the 'aforesaid shoulders to resilientlycontact said sleeve uniformly along the length thereof, yet arranged tocontact the tubular hood of the assembly upon insertion of a pin intosaid split sleeve to prevent permanent deformation of the jaws byflexing beyond l their elastic limit.

References Cited by the Examiner f UNITED STATES PATENTS 2,346,8314/1944 Drury 17a-'Jans 2,503,406 4/1950 Osterrnan et al 173--3633,003,135 10/1961 ylurinton 339-262 FOREIGN PATENTS 1,074, 1-10 2/1957Germany.

555,416 1./ 1957 Italy.

EDWARD C. ALLEN, Primary Examiner. JOSEPH D. sEERs, Examiner.

J. McGLYNN, Assistant Examiner.

